The long term objective of these studies is to understand the role(s) of polyunsaturated fatty acid-containing lipids in the physiological role of the testis (i.e., the production of healthy spermatozoa). These polyenoic acid-containing lipids (such as phospholipids) are vital for the structural integrity and proper physiological functioning of the testis. Nutritional and hormonal factors are important for the regulation and control of the concentrations and the metabolic processes of these compounds. In these investigations both hormonal and nutritional effects will be included. One phase deals with the effect of hypophysectomy on the biochemical conversion of members of the linoleic acid family to docosa-4,7,10,13,16-pentaenoic acid in rat testes and in particular cell types of the testis and the role of certain hormones in preventing or reversing such effects. Another phase deals with the effect of a deficiency of vitamin E, of vitamin A and of zinc on the polyenoic acid metabolism of Sertoli and germinal cells. 14C-labeled members of the linoleic acid family will be used as substrates in in vivo (intratesticular injectiona) and in vitro (incubations of microsomes, of germinal and Sertoli cells, and of primary cultures of Sertoli cells). Metabolic steps inhibited by hypophysectomy will be identified and prevention or reversal by hormone replacement therapy attempted. The effect of these factors on retroconversion of 22-carbon polyenes to arachidonic acid will be determined. Thin-layer and gas chromatography will be used for separation of lipids and of fatty acids. 14C-labeled determination of individual lipid classes and fatty acids will be determined (thin-layer and radio gas chromatography). These studies should contribute to our understanding of the process of production of normal ("healthy") spermatozoa and of problems of fertility and infertility.